Over 70% of complications which occur with hemodialysis are caused by access failure. Hemodialysis catheters are one set of access devices which yield access failure due to thrombosis, stenosis, access recirculation, and low flow rates. Many of these problems result from inadequate design of the catheters with respect to access fluid dynamics. The goal of the proposed study is to develop (design and fabricate) and test improved hemodialysis catheters. Both numerical and experimental investigations will be pursued with advisement from clinical users (UAB Division of Nephrology) and industrial manufacturers (Cook Critical Care) of the devices. The Phase I study will commence with a state-of-the-art computational fluid dynamics analysis of promising catheter design improvements. The best new catheter designs will be selected for prototype fabrication based upon the minimization of shear rates, access recirculation, and flow resistance in the CFD studies. The prototypes will be evaluated along with commercially available catheters in an in vitro flow loop designed to demonstrate fluid flow and access recirculation. The in vitro performance of the prototype catheters will identify further design improvements, ultimately culminating with in vivo testing in Phase II and commercialization in Phase III. PROPOSED COMMERCIAL APPLICATION: The improved catheter design(s) developed in this study will have a direct impact on patient well-being through a more efficient hemodialysis process with a lower risk of thrombosis. This device will be marketed to hemodialysis catheter manufacturers such as Baxter Healthcare and Cook Critical Care, who in turn will offer the device to caregivers of the more than 200,000 currently enrolled dialysis patients.